Merge remote-tracking branch 'qatar/master'

* qatar/master:
  mp2: Do not force a samplerate

Conflicts:
	libavcodec/mpegaudioenc_template.c

Only libtwolame changes, as the forcing of a sample rate was not merged for the native mp2 encoder
Merged-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/libtwolame.c

@@ -191,7 +191,6 @@ static const AVClass twolame_class = {
 
 static const AVCodecDefault twolame_defaults[] = {
     { "b", "384000" },
-    { "ar", "48000" },
     { NULL },
 };